As discussion of erecting a security fence along U.S. borders with Mexico and Canada heats up, some analysts say it’s possible Washington could economically erect thousands of miles of barrier to keep out illegal aliens, smugglers and terrorists, for about half of what the Pentagon is spending a month to fight the war on terror.

The idea, they say, is to erect a structure similar to barrier walls built along highways to reduce sound. They are sturdy, tall, not easily scaled and, most attractively, affordable.

The Federal Highway Administration says most highway sound barriers are constructed of concrete or masonry block, range from 3-5 meters [9-16 feet] in height, and cost between $175 and $200 a square meter.

By comparison, the Pentagon is spending about $3.9 billion a month in Iraq and Afghanistan, not counting rebuilding costs, the Associated Press has reported.

One group, WeNeedAFence.com, is advocating the construction of a “state-of-the-art fence” along the entire U.S.-Mexico border, a plan it says would dramatically reduce illegal immigration.

The group points to the fact that similar security fences in Israel have reduced terrorist attacks there by as much as 95 percent in some regions.

Lee Plank, executive vice president and chief operating officer of Diamond Manufacturing Company in Wyoming, Pa., says his company has not been approached about border security fences, but, he said, they would be a good idea.

“I think they’d have to be about 10 feet high,” he told WND, and would cost “about $636,000 a mile” to build. That’s about $1.27 billion for 2,000 miles of border fence, similar to the government’s figures.

Plank, who says his company specializes in sound-absorbing corrugated metal walls, said a border security fence “would save a lot on manpower.”

“It would be interesting to see them on the borders,” he added.

Mike Flick of Oldcastle Precast Group, a nationwide leader in both highway and security fencing, told WND the idea of border fencing is certainly doable, but the design, depth and other particulars would need to be worked out.

Some have criticized the idea of a border fence.

“The United States needs a better immigration policy, not a fence along the border with Mexico that won’t do anything to protect us anyway,” says an editorial in the Modesto Bee. “The proposed fence is simply a sign of frustration with illegal immigration. Our politicians need to come up with workable solutions to the problems of illegal immigration and national security.”

WeNeedAFence.com officials say a border fence makes sense in this day and age.

“The problem is not merely the number of illegal immigrants. In addition to the hundreds of thousands of illegal immigrants from Central and South America, there are several hundreds, perhaps thousands, of illegal aliens from countries that sponsor terrorism or harbor terrorists entering the United States each year across our border with Mexico. Thus, it is a national security issue as well as an immigration issue,” the group says on its website.

Officials at the Department of Homeland Security also believe in erecting new fences or strengthening existing ones as a way to bolster security. Last month DHS quietly implemented a pair of measures aimed to bring regions of the southwestern border under control

One measure “makes it easier for officials to remove non-Mexican illegal immigrants, popularly called ‘other than Mexicans’ or OTMs,” U.S. News & World Report said, “while another adds yet one more level of fortification to a metal wall stretching along parts of the border.”

“They clearly did this when no one was looking,” complained Tim Edgar, an immigration specialist with the American Civil Liberties Union. “And I’m worried DHS is trying to set new norms for how we treat immigrants in the United States.”

Border Patrol agents have praised fences as a means to deter border-jumping. One San Diego-area agent, speaking on anonymity, told WND fences constructed there have “dramatically” reduced the incidents of illegal immigration, though, the agent conceded, many immigrants have merely moved inland, east of the area where the San Diego fence line ended, to sneak into the country.